Dear Doctor, Part I: High LDL Readings

The letter below is the first of a series of letters to my doctor about the impact of my low carb lifestyle on my health. I have no idea how she will react to my health tests, so these are "just in case." But I thought it would be useful to collect the relevant information in one place, so I (and others) can show physicians why statin drugs may not be appropriate in every case. Where possible, I will link to the relevant studies from the medical literature. Future letters will discuss HbA1c results, diabetes drugs, cardiovascular health, "healthy" eating, and any other subjects I find interesting.

Dear Doctor:

I have been following a low carb diet for over six months now and you recently prescribed a lipid profile for me. The results are in and they are generally good. My HDL cholesterol level is up, my triglycerides are down, and my total cholesterol number is acceptable. Yet you want to prescribe a statin drug for me because my LDL cholesterol reading is high.

Consider this: the LDL cholesterol in my blood was never measured; it was calculated, using this formula[1]:

   LDL=Total Cholesterol -[HDL + (triglycerides/5)]

Why is this calculation a problem? It overestimates the presence of LDL cholesterol. If we assume that a low carb diet lowered my triglycerides (a good thing), but total and HDL cholesterol numbers stayed the same, this is what we would have:

                               Total              HDL         TRI         LDL (Calculated)
Before LC Diet          200               60           200            100
After LC Diet            200                60            75             125

So lowering triglycerides (a good thing), causes the LDL number to go up (a bad thing, in your opinion), based on the above equation. But what is my actual LDL, not the calculated LDL? We don't know, because you did not test for it. You could have ordered an NMR lipoprofile test to learn the actual measure, but you did not. So all we are left with is a problematic calculated value.

Also, are all LDL particles equally bad? The calculated number says nothing about the size of the LDL particles. Are they large and fluffy (also referred to as pattern A particles), or small and dense (also referred to as pattern B particles)? The large and fluffy LDL particles are not dangerous, and may even be somewhat beneficial, but recent research also shows that the small, dense, and sticky LDL particles are the real danger signal for heart disease.

But that new test to determine particle size may be expensive. Fortunately, there is a workaround. Take the ratio of my triglycerides to HDL (Triglycerides/HDL), which is an effective surrogate of the NMR lipoprofile test. If the ratio is below 3.5, I probably have pattern A and if it is above 3.5, I probably have pattern B. If I have pattern A LDL particles, I do not need a statin drug to lower my cholesterol.

Since my HDL went up and my triglycerides went down, I probably have pattern A particles, which are beneficial, not dangerous. So I respectfully decline your invitation to put me on statin drugs.

Sincerely,

[1] I learned much of the information in this letter from reading The Art and Science of Low Carbohydrate Living by Jeff S. Volek, Ph.D., R.D. and Stephen D. Phinney, M.D., Ph.D., pp. 91-95. The example used is taken from these pages.

"Bad" Cholesterol is Not So Bad

One problem with a low carb diet is that it can cause your LDL (or "bad") cholesterol to rise.  As I have explained before, this is not necessarily bad, as long as the LDL particles are large and fluffy, not small and dense.

Now a recent research study suggests that the "bad" cholesterol is not as bad as previously thought.  In this study, people who exercised and gained muscle mass had the highest LDL levels, a surprising finding.  I enjoyed reading how the researchers had to spin the findings, since exercise and gaining muscle mass is generally considered a good thing.  More ammunition that the "bad" cholesterol is not always bad.

Health Benefits of Following a Low Carb Lifestyle

After honestly following the low carb lifestyle for three months, you should expect the following to occur when you have blood work analyzed on your next visit to the physician, especially if you are a type II diabetic.  I have seen this information in a wide variety of sources, including Good Calories, Bad Calories and Why We Get Fat by Gary Taubes, an article by Michael R. Eades, M.D., and many other sources.

Weight loss.  If you are consuming 30 or so grams of carbs or less, you should show a substantial weight loss.

HgbA1c.  Your blood glucose profile should show substantial improvement over your previous reading, since carbohydrates drive blood glucose levels.  Eliminate the carbs, improve your blood glucose profile.

Total Cholesterol.  This will probably drop, but not by a great deal.  But this doesn’t tell the whole story.  Read on.

HDL Cholesterol (the “good” cholesterol”).  This reading should go way up.  This is a major benefit from eating all of those foods laden with saturated fats.

Triglycerides.  This number should go way down.  This is good for two reasons.  First, lower triglycerides correlate with greater insulin sensitivity, meaning your pancreas doesn’t have to work as hard.  Second, it correlates with larger LDL-cholesterol size (see below).

LDL Cholesterol (the “bad” cholesterol).  This reading may go up, into the worse range, and may cause your physician, if she or he is not up on the latest information, to express some concerns.  They might even want to put you on drugs to bring this number in line.  Don’t let her/him do this to you!  Small, dense LDL cholesterol particles are associated with increased risk for heart disease, but the larger, fluffy LDL cholesterol particles may actually protect you from heart disease.  LDL particle size is typically not measured in a lipid profile, but as triglyceride levels go down, LDL particle size goes up.  So if you have dramatically better triglyceride levels, you probably have the larger, fluffy, protective LDL particles in your blood.  On the other hand, if you have high triglyceride levels and low HDL levels, you are at much greater risk of heart disease from small, dense LDL cholesterol particles.

Triglyceride/HDL Ratio.  The lower this ratio is the better.  The low carb diet works dramatically better than the low fat, high carb diet at reducing this ratio.

Blood Pressure. You should see a significant lowering in your blood pressure.  Both systolic and diastolic blood pressure readings should go down.

Overall, you should experience a much lower risk of cardiovascular disease.

And just so you know that I am not making this stuff up, Gary Taubes has just posted his most recent lipid profile online (April 18, 2011), along with his daily menu (eggs, bacon, sausage, cheese, hamburger, butter, and a pound of steak for dinner).  Note that I wrote all previous paragraphs of this post before I discovered Taubes’ lipid profile online.